Crane boom load height, radius, angle, and elevation indicator



Jan. 15,1963

W. E. THIEL CRANE BOOM LOAD HEIGHT, RADIUS, ANGLE, AND ELEVATION INDICATOR Filed Sept. 11, 1961 5 Sheets-Sheet 1 i BOOM AT 72 DEGREES INVENTOR 19.63 w. E. THlEL 3,073,280

CRANE BOOM LOAD HEIGHT, RADIUS, ANGLE, AND ELEVATION INDICATOR Filed Sept. 11, 1961 5 Sheets-Sheet 2 OOM ,AT 72 IN VEN TOR.

DEGREES Jan. 15, 1963 w; E. THIEL 3,07

CRANE BOOM LOAD HEIGHT, RADIUS, ANGLE, AND ELEVATION INDICATOR Filed Sept. 11, 1961 5 Sheets-Sheet :5

Boom AT 72 DEGREES INVENTOR.

Jan. 15, 1963 w. E. THIEL 3,073,280

CRANE BOOM LOAD HEIGHT, RADIUS, ANGLE, AND ELEVATION INDICATOR 5 Sheets-Sheet 4 Filed Sept. 11, 1961 Jan. 15, 1963 w. E. THIEL 3,073,280

CRANE BOOM LOAD HEIGHT, RADIUS, ANGLE, AND ELEVATION INDICATOR Filed Sept. 11, 1961 5 Sheets-Sheet 5 A; Z N Flu] 5 R 6 IN VEN TOR.

Patented Jan. 15, 1963 3,073,280 CRANE BOOM LOAD HEIGHT, RADIUS, ANGLE, AND ELEVATION INDICATOR Walter E. Thiel, 3200 Netherland Ave., New York 63, NY. Filed Sept. 11, 1961, Ser. No. 137,204 1 Claim. (Cl. 116-124) This invention relates to an improved indicator and more specifically to simultaneous indication of maximum allowable crane boom loads, crane boom heights, boom operating radii, boom angles and boom elevations.

This invention is distinct from United States Patent No. 3,012,537.

The principal objective of this invention is to provide an indicator which simultaneously indicates the maximum allowable boom load in tons at all angles used or indicated to reduce future loss of life and property due to crane accidents.

Another objective is to provide an indicator which simultaneously indicates the operating radius in feet at all boom angles used or indicated.

Another objective is to provide an indicator which simultaneously indicates the top height of boom at all angles used or indicated.

A further objective is to provide an indicator which indicates the boom angle used, and which also graphically indicates the boom elevation at all angles used or indicated.

Another objective is to provide an indicator which performs all of the above-mentioned operations simul taneously, and other advantages in construction and arrangements will be apparent from descriptions and drawings of which:

FIG. 1 is a plan view of indicator for booms where indicator is attached to left side of boom structure.

FIG. 2 is a similar plan view of indicator for booms where indicator is attached to right side of boom structure.

FIG. 3 is a plan view of indicator for booms with jib where indicator is attached to left side of boom structure.

FIG. 4 is a similar plan view of indicator for booms with jib where indicator is attached to right side of boom structure. I

FIG. 5 is a sectional view of FIG. 1 and FIG. 3 on line 11.

FIG. 6 is a sectional view 2-2.

FIG. 7 is a diagrammatic view of a hoisting crane.

FIG. 8 is a diagrammatic view of a hoisting crane with a jib attached.

Referring to drawings FIGS. 1 to 4 show an indicator designated by reference numeral 10, in the form of a thin circular disc of metal, plastic or other suitable material. The surface of this disc is divided into four quadrants, indicated by the numerals 12, 13, 14 and 15, the quadrants being marked off from each other by symbols 11 along the periphery of the disc; each quadrant bears suitable legends together with appropriate graduations along its periphery.

Section 12 shows graduations through a range of eight tons, indicating the maximum allowable boom loads; the numbers in the scale, A1, 1%, 1 /2, 2, 3 /2, 4%, and 8, indicate tons and fractions of tons which the boom can lift as specified by the crane manufacturer for indicated boom angles.

Section 13 shows graduations indicating the operating radius of boom in feet; the large number designated in section 14, FIGS. 1 and 2, by the numeral 16 (in the example illustrated this number is l50), indicates the boom length in feet. In FIGS. 3 and 4 the number indicated by the reference numeral 17 is the combined of FIG. 2 and FIG. 4 on line length of boom and jib, and the peripheral graduations indicate operating radius in feet for this boom with jib.

Section 14 shows graduations indicative of the boom angle in degrees and an additional graduated arc 18 is provided concentric with the peripheral graduations and radially aligned therewith for convenience in reading the boom angle.

Section 15 shows graduations indicative of the boom height in feet, which indicate the maximum allowable height of the boom when used at indicated angles on FIG. 1 and FIG. 2, and which in FIGS. 3 and 4 indicate the total height of the boom and jib above ground when used at indicated angles.

A smaller disc 19 having four pointers 20, 21, 22 and 23 co-planar therewith and a quadrant apart, rotates in unison with the boom. Pointer 20 indicates 0n the large disc Ill-maximum allowable boom loads in tons, pointer 21 indicates on the large disc 10 the operating radius in feet, pointer 22 indicates the boom angle in degrees, and pointer 23 indicates the boom height in feet. The pointers 20 and 22 have a triangular lower end 24 and represent graphically the boom at all elevations.

The smaller disc 19 with its four pointer 20, 21, 22, 23 of metal is firmly attached to a headed bolt 25 on the central axis of the boom by spot welding 26. The opposite end of bolt 25 is threaded and passed through an aperture in the side of the boom and is firmly attached to boom 27 by a nut 28. A flanged sleeve 29 is provided for the shank of the bolt 25 to maintain ample space for free movement of disc 10 on the central axis, with Washers 30 and 31 on both sides of disc 10. A small metal plate 32 is spot welded at 33 to lower back side of disc 10 in order normally to maintain the disc when at rest by the force of gravity, in the positions thereof shown in FIGS. 1-4, that is, with the topmost and lowermost symbols 11 positioned in a vertical line. Thus the disc 10, in case it should swing or move on its axis, will always come to rest in the position shown in the said figures of the drawing.

The indicator is mounted on a longitudinal center line of the boom at a height convenient for visual observation by the operator, as indicated on FIG. 7 and FIG. 8 which respectively show diagrammatically the disc 10 attached to a single boom 27 and to a boom 27 with a jib, this jib being identified by the letter A. When the boom is raised, the four pointers rotate clockwise, and when the boom is lowered the pointers rotate counterclockwise. Since the disc 10 which is rotatable on its axis but always maintains the true vertical position above mentioned, the pointers respectively indicate the boom loads in tons, boom operating radius in feet, boom angle, boom elevation and top height of the boom.

, In the case of a crane rated for a foot extra heavy duty boom with a 50 foot jib attached, the maximum allowable load is 4% tons, for which the crane manufactures specify a boom angle of 72 degrees to the horizontal. An example of this case is illustrated in FIGS. 1-4 of the drawing. When the boom is raised to 72 degrees as indicated -by the lower triangular end 24 of pointer 22, the pointer 20 simultaneously indicates the maximum allowable load at 4% tons which informs the operator that this boom angle of 72 degrees to the horizontal must be maintained for safe lifting.

Simultaneously pointer 21 indicates the operating radius at 66 feet, which is the distance from the center of rotation 34 of the crane to center of the load 35; in this example the distance from the center of rotation 34 to the boom foot pin 36 has been assumed at 4 feet.

At the same time the pointer 23 indicates the height of jib A at feet, measured to the tip 37, FIG. 8. The height of 195 feet is the total vertical distance from ground 38 to the boom foot pin 36 and the combined 3 height of boom 27 and jib A computed when at an angle of 72 degrees to the horizontal.

Also at the same time pointer 22 with triangular end 24 indicates the boom angle, and together pointers 20 and 22 graphically indicate the booms elevationat all angles used. When the boom is raised all the pointers simultaneously rotate clockwise and indicate higher boom angles in degrees, higher boom loads in tons, a lower operating radius, and a higher boom elevation; when the boom is lowered all pointers simultaneously rotate counter clockwise and on disc 10 they indicate smaller boom loads in tons, a larger operating radius in feet, a lower boom angle, smaller boom height and a smaller boom elevation.

Having described and illustrated my invention, which however is not to be considered as restrictive, changes and modifications are possible and may be embodied in other specific forms within the aim of appended claim, what I claim as new and for which I desire to secure a United States Letters Patent is:

An indicator for use with a crane boom pivotally mounted at one end to rotate on a horizontal axis in a vertical plane, comprising a first flat disc having one face thereof divided into four quadrants each extending through ninety degrees of are, each quadrant having a scale at its periphery, the scales representing respectively maximum allowable loads for the boom, heights of the boom, operating radii of the boom, and angles of the boom; an indicating device comprising a second fiat disc of smaller diameter than the first disc having four coplanar pointers spaced ninety degrees apart and extending radially from the second disc; a horizontal shaft mounted on one side of the boom on a longitudinal center line of the boom, a sleeve surrounding the shaft, said second disc being rigidly mounted on said shaft in a position spaced from said side of the boom, said first disc being pivotally mounted on its axis on said sleeve in the space between said side of the boom and said second disc, the pointers having a length sufficient to extend radially outward to terminate at the respective scales, said first disc having at the periphery thereof four spaced symbols positioned at the dividing lines between the quadrants, said first disc having a metal plate secured to the lower portion of the other side thereof with the weight of the plate equally proportioned on each side of a diameter of the disc passing through two diametrically opposed symbols whereby the plate is normally maintained by gravity in a position wherein said two symbols are vertically aligned and whereby the respective pointers indicate the maximum allowable load for the boom, height of the boom, operating radius of the boom and the angle of the boom.

Jackson Jan. 4, 1938 Thiel Dec. 12, 1961 

